Improvement in piano-eooks



JOHN THIELEMANN, OF NEWARILNEW JERSEY.v

Letters 'Patent No. 81,226, dated August 18, 1868.

` IMPROVEMENT IN PIANO-LOCKS.

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TO ALL WHOM IT MAY CONCERN;

Be it known that I, JOHN THIELEMANN, of Newark, in the county of Essex, in the State ot' New Jersey,

have invented a new and useful Improvement in Piano-Loolis;,and I do hereby declare the'followingto be a.

full, clear, and exact description, which will enable those skilled in the art to make and use thesame, reference being had to the accompanying drawing, forming part of this specification, in which drawing- Figure l represents a sectional front view of this invention when the hook-bolts are in.

Figure 2 is a similar section thereof when the hook-bolts are out.

Similar letters indicate corresponding parts.

This invention consists in the arrangement of two hook-bolts, which are united -by a slotted lug and pin,

-and the inner edges of which form cams, which, when the hook-belts are thrown out, act against a stationary stud in such a manner, that, by turning the key in one direction, said hook-bolts assume a compound motion, viz, a motion outwardrand also a motion from eachother, whereby the hooks are enabled to catch over the edges of the locking plate, and by turning the key in the opposite direction, the hook-bolts are made to move towards each other, and to recede, thereby releasing the locking. plate. Y

A represents the base or foundation-plate of my lock, said plate being firmly secured to the face-plate B.

From the base-plate A rise two studs, a a', which" catch in oblique slots in the shanlzs of the hook-bolts C C. These tWohooli-bolts are connected by a slotted lug, b, catching over a stud, b', the lug being connected to one and the stud to the other bolt, as shown in thedrawing, and one ot thc bolts 4is provided with a notch, c, and tumbler y, so that it can be thrown in and out by the action ef a key in the usual manner. Between the shanks of the two hook-bolts is a stud, (Z, which is firmly secured in the bascplate A, and the inner edges of the Shanks of said hook-l olts foren cams, e e', which act against the stud d.

When the key is turned in the direction of the arrow shown in iig. 1, it catches into the notch c, lifts up the tumbler g, and pushes the hook-bolt C ont, and by the action of the lug band stud b', the hook-bolt C is carried out together witlrthe bolt C. As the cams e e are made to slide on the stud cZ, the hook-bolts begin to splread,`and the hooks, being thrown ont tothe position shown in iig. 2, are made to catch over the edges of the locking-plate. If the key is turned in the direction of the arrow, 'shown in g. 2,'the hooks are made to release the locking-plate, and the bolts are carried back to their original position.

When the bolts are brought back to this position, they close the opening `in the face-plate, so that the entrance of dirt or other impurities to themechanism of the lock is prevented.v

Having thus described my invention, what I claiin as new, and desire to secure by Letters Patent, is-

The hook-bolts C C', connected together by a lug and stud, and provided with cams ve e', in combination with a stud, d, substantially as and, for the purpose described. I

Witnessest W. HAUFF', E. F. KAsTENnUnEn.

lOHN THIELEMANN. 

